The invention relates to an aqueous hair and body treatment composition containing a combination of (a) hinokitiol and (b) heliotropin.
As a rule, hair and body treatment compositions contain a preservative which should effectively protect the composition from infection by microorganisms, as well as fragrances to give a pleasant aroma to the compositions.
When preservatives are used in hair and body treatment compositions, conflicting demands are made on them. On the one hand, they should be well tolerated in physiological and dermatological respects. On the other hand, they should have a good germ inhibiting or even germ killing action. Usually, the two demands can be reconciled only with difficulty.
Preservatives commonly used in hair and body treatment compositions are e.g. formaldehyde (a), 5-bromo-5-nitro-1,3-dioxane (b), p-hydroxybenzoic acid ester (c), 2,4,4'-trichloro-2'-hydroxydiphenyl ether (d), 5-chloro-2-methyl-3-isothiazolone (e), 2-methyl-3-isothiazolone (f), and 2-bromo-2-nitropropane-1,3-diol (g).
Certain preservatives such as formaldehyde and 2-methyl-3-isothiazolone are currently suspected of being insufficiently tolerated. Aldehydes and phenols having a preservative action are known to react with proteins or to interact with them in a denaturing manner. Aldehydes carry the additional risk of sensitization.
Another risk which argues against the use of such preservatives is the danger of nitrosamine formation. In preservatives containing nitro groups ((b) + (g)), this risk is particularly high when they are used together with other nitrogen-containing components of the cosmetic composition.
For this reason, an increasing number of consumers show a desire for hair and body treatment compositions which do not contain the preservatives mentioned above and which have, in addition, a pleasant and stable aroma.
Repeated attempts have already been made to replace the conventional preservatives with new substances with improved physiological tolerability, but none of the new compounds were able to satisfy all requirements.
For example, in the present Applicant's EP-OS 0 346 582 it was suggested to use cosmetic alcohols, e.g. ethanol, propanol or isopropanol, for preserving anionic hair care emulsions. However, a disadvantage consists in that at least 9 percent by weight alcohol is required for sufficient preservation, which can impair the stability of the emulsion.
It is also known from the literature in the field, e.g. B. Ziolkowsky, "Konservierung kosmetischer Mittel [Preservation of Cosmetic Compositions]", in Seifen-Ol-Fette-Wachse [Soaps, Oils, Fats and Waxes] 112 (10), pages 355 to 364, to use hinokitiol for preserving cosmetic compositions. However, it is noted that hinokitiol is also not suitable in higher concentrations for preserving oil-in-water emulsions. In view of the high price of hinokitiol, the use of higher concentrations also appears impractical on economic grounds.
Heliotropin, one of the principle substituents of elderberry fragrance, is likewise poorly suited for preserving cosmetic compositions, since more than 0.5 percent by weight heliotropin is required for sufficient preservation, which results in a serious impairment of the aroma of the cosmetic composition.